Seeduino v2.21 not programming through USB

My Seeeduino V2.21 no longer seems to be able to be programmed through the USB port. It was working before but now Windows will not recognize it. I uninstalled and reinstalled the drivers for the COM port but that has not worked. I was able to program through an FTDI breakout board and run Blink so it appears to be the USB. Any ideas on how to get it working?


May be something happen with your Bootloader.